Flow-microcalorimetry measurements of aerobic and anaerobic soil microbial activity     

Bert P. Albers  Friedrich Beese  Anton Hartmann 《Biology and Fertility of Soils》1995,19(2-3):203-208

Heat output can be used as an indicator of microbial activity and is usually measured in a microcalorimeter with closed ampoules. In long-term experiments particularly, interpretation of the data is hindered by the changing environment in the closed ampoules because of O₂ consumption and CO₂ enrichment. We used a combination of a flow-microcalorimeter and a gas chromatograph to measure the heat flux and CO₂ and N₂O production rates under controlled conditions. Simultaneous detection of the heat output and CO₂ emission allowed calculation of the calorimetric: CO₂ (Cal/CO₂) ratio. A mean ratio of-435 kJ mol^-1 CO₂ was detected in six different soils amended with glucose and incubated under aerobic conditions. This ratio indicated that CO₂ was the end-product of catabolism. In wet 10–12 mm soil aggregates of a gleyic vertisol amended with glucose, values of-285 kJ mol^-1 CO₂ under an aerobic and-141 kJ mol^-1 CO₂ under a N₂ atmosphere was determined. These findings indicated that fermentative metabolism occurred. The Cal/CO₂ ratio was not affected when enough NO _inf3 ^sup- was available and denitrification processes (N₂O production) were possible.  相似文献   

Continued freedom from blue-tongue virus infection in cattle and sheep in Western Australia south of latitude 26° S     

TM ELLIS  R. TURNOR  TT NGUYEN  U. TARNOWSKI 《Australian veterinary journal》1996,74(4):317-319

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Cassini dust measurements at Enceladus and implications for the origin of the E ring     

Spahn F  Schmidt J  Albers N  Hörning M  Makuch M  Seiss M  Kempf S  Srama R  Dikarev V  Helfert S  Moragas-Klostermeyer G  Krivov AV  Sremcevic M  Tuzzolino AJ  Economou T  Grün E 《Science (New York, N.Y.)》2006,311(5766):1416-1418

During Cassini's close flyby of Enceladus on 14 July 2005, the High Rate Detector of the Cosmic Dust Analyzer registered micron-sized dust particles enveloping this satellite. The dust impact rate peaked about 1 minute before the closest approach of the spacecraft to the moon. This asymmetric signature is consistent with a locally enhanced dust production in the south polar region of Enceladus. Other Cassini experiments revealed evidence for geophysical activities near Enceladus' south pole: a high surface temperature and a release of water gas. Production or release of dust particles related to these processes may provide the dominant source of Saturn's E ring.  相似文献   

A comparison survey of organic and conventional broiler chickens for infectious agents affecting health and food safety     

Van Overbeke I  Duchateau L  De Zutter L  Albers G  Ducatelle R 《Avian diseases》2006,50(2):196-200

The purpose of the present cross-sectional study was to evaluate the health status of organic broiler chickens and the contamination rate with Salmonella and Campylobacter in organic broiler production in Belgium. The broilers were screened for antibodies against routinely monitored poultry diseases at 1 day old and at slaughter. Fecal examination for the presence of worm eggs was done at slaughter. Bacteriological examination for the detection of Salmonella and Campylobacter was performed at day 1, week 2, week 4, week 7, week 10, and slaughter. Conventional broilers of the same poultry integration and reared in the same geographic area were also screened and served as reference. Serologic data indicated lower antibody titers against infectious bronchitis and Newcastle disease in organic flocks. No significant differences could be found in prevalence of Salmonella between organic and conventional broilers at slaughter. In contrast, Campylobacter infections at slaughter were significantly higher in organic flocks. Organic flocks most probably become infected with Campylobacter between week 7 and week 10. Worm eggs were found in neither the organic flocks nor the conventional flocks. In conclusion, there are indications that the respiratory health status is better in organic broilers but that organic flocks are more often infected with Campylobacter than are conventional flocks.  相似文献   

A systematic survey of loss-of-function variants in human protein-coding genes     

MacArthur DG  Balasubramanian S  Frankish A  Huang N  Morris J  Walter K  Jostins L  Habegger L  Pickrell JK  Montgomery SB  Albers CA  Zhang ZD  Conrad DF  Lunter G  Zheng H  Ayub Q  DePristo MA  Banks E  Hu M  Handsaker RE  Rosenfeld JA  Fromer M  Jin M  Mu XJ  Khurana E  Ye K  Kay M  Saunders GI  Suner MM  Hunt T  Barnes IH  Amid C  Carvalho-Silva DR  Bignell AH  Snow C  Yngvadottir B  Bumpstead S  Cooper DN  Xue Y  Romero IG; Genomes Project Consortium  Wang J  Li Y  Gibbs RA  McCarroll SA  Dermitzakis ET  Pritchard JK  Barrett JC 《Science (New York, N.Y.)》2012,335(6070):823-828

Genome-sequencing studies indicate that all humans carry many genetic variants predicted to cause loss of function (LoF) of protein-coding genes, suggesting unexpected redundancy in the human genome. Here we apply stringent filters to 2951 putative LoF variants obtained from 185 human genomes to determine their true prevalence and properties. We estimate that human genomes typically contain ~100 genuine LoF variants with ~20 genes completely inactivated. We identify rare and likely deleterious LoF alleles, including 26 known and 21 predicted severe disease-causing variants, as well as common LoF variants in nonessential genes. We describe functional and evolutionary differences between LoF-tolerant and recessive disease genes and a method for using these differences to prioritize candidate genes found in clinical sequencing studies.  相似文献   

Hunting behavior of a marine mammal beneath the antarctic fast Ice   总被引：1，自引：0，他引：1  

RW Davis  LA Fuiman  TM Williams  SO Collier  WP Hagey  SB Kanatous  S Kohin  M Horning 《Science (New York, N.Y.)》1999,283(5404):993-996

The hunting behavior of a marine mammal was studied beneath the Antarctic fast ice with an animal-borne video system and data recorder. Weddell seals stalked large Antarctic cod and the smaller subice fish Pagothenia borchgrevinki, often with the under-ice surface for backlighting, which implies that vision is important for hunting. They approached to within centimeters of cod without startling the fish. Seals flushed P. borchgrevinki by blowing air into subice crevices or pursued them into the platelet ice. These observations highlight the broad range of insights that are possible with simultaneous recordings of video, audio, three-dimensional dive paths, and locomotor effort.  相似文献   

Pulmonary Maturation in Canine Foetuses From Early Pregnancy to Parturition     

TM Sipriani  F Grandi  LCG da Silva  PC Maiorka  CI Vannucchi 《Reproduction in domestic animals》2009,44(S2):137-140

Development of the foetal respiratory system includes both pulmonary growth and maturation. In human medicine, a higher incidence of respiratory distress is reported in newborn males. This study aimed to identify different phases of canine foetal lung maturation throughout pregnancy, to determine the stage of pregnancy in which surfactant production begins and to compare pulmonary development of male and female foetuses. Pregnant bitches (34) were subjected to elective ovariohysterectomy and allocated into four groups, according to the stage of pregnancy: 30–40 days of pregnancy (n = 10), 41–50 days (n = 10), 51–60 days (n = 10) and bitches in the first stage of parturition (n = 4). Foetal lungs were histologically processed and evaluated by optical microscopy. The pseudoglandular phase was identified between the 35th day and 46th day of gestation; the onset of canalicular and saccular periods was observed, respectively, from the 48th day and 60th day of pregnancy. Lungs from foetuses at term were in the saccular phase; thus, the development into the alveolar period occurs in the neonatal period. The histological analyses revealed that respiratory tract development is centrifugal, from upper to lower airways. Therefore, it is possible to identify distinct development periods in different portions of the same organ. In conclusion, the saccular phase of lung development begins around 57 and 60 days of pregnancy, the period in which surfactant production is believed to occur. Male and female foetuses present similar pulmonary development from early pregnancy until parturition.  相似文献   

Importance of Staphylococcus hyicus ssp hyicus as a cause of arthritis in pigs up to 12 weeks of age     

BD HILL  BG CORNEY  TM WAGNER 《Australian veterinary journal》1996,73(5):179-181

Lame pigs, up to 12 weeks of age, were necropsied to establish a diagnosis. Of 175 pigs examined, 165 were confirmed to have arthritis by histopathological examination of joint tissues. Lesions were most common in the elbow and tarsal joints and least common in the joints of the feet. Typically, there was severe fibrinopurulent inflammation of synovial membranes regardless of the bacteria isolated. A bacterial aetiology was found in 114 (69%) of the 165 pigs. In arthritic pigs in which an aetiology was established the causative agents were Staphylococcus hyicus ssp hyicus (24.6%), Streptococcus equisimilis (26.3%), Actinomyces pyogenes (13.2%), Staphylococcus aureus (7.9%) and Haemophilus parasuis (7.9%). While gender did not affect the prevalence of arthritis, there was an age influence, most of the pigs culled for arthritis being under 6 weeks of age.  相似文献   

Encephalomyocarditis virus infection in pigs     

AR MERCY  RL PEET †  TM ELLIS †  J. PARKINSON † 《Australian veterinary journal》1988,65(11):355-355

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Government Animal Health Laboratory Services in Western Australia   总被引：1，自引：1，他引：0  

RB RICHARDS  TM ELLIS  JG ALLEN 《Australian veterinary journal》1993,70(9):321-323

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